Naval History Forums

Hi Bill: I am examining just one of the variables involved in shell flight -- and am not out to prove anything. You mention the 2,400 pound projectile, but the example here is the 2,240 pound projectile vs the 2,700 pound projectile. The general concept is to examine the behavior of a shorter and li...

... although on occasion they can be found in the plans. No such luck here. The reason I bring this up is because the location of the center of mass relative to the center of air pressure resistance may be a factor here in the relative flight stability of the two shells -- and especially at the summ...

I well understand your point about teasing apart the other variables from possible yaw effects themselves, and that is one of the reasons I am so uncertain about the exercise. Indeed, it may be pointless, but let us test run it for a bit. The 16" shells in question have different physical chara...

Hi All:

We're still looking for a the detailed report on the Bismarck's sea trials -- which we want to translate. Any help would be welcome.

George

Hi Bill: I am not at all sure how to begin a discussion on this subject, and I have contemplated a number of examples that may be useful. It strikes me that we ought to consider shells that have much in common, but that may differ in one or two details that could be tied to flight dynamics. Along th...

... and see how totaly out in la-la land you truely are, and especially after shooting yourself in both feet on the subject. As for the Goldsmith article, how can you disscuss the efficacy of a study you never read -- let alone judge anyone's reaction to it? You're just blowing hot air and everyone ...

I hate to ask him because he is so busy, but Dr. Don C. may be of considerable use here. You probably already know him. He is a no flame sort of guy, and that is why I am hesitant to get him into this food-fight arena. But he is from the old school, and even uses problems involving large naval shell...

Hi Jose: You may be right about a yaw-specific thread being in order wherein the expert literature can be examined. I seem to recall vague claims being made in another thread regarding the supposed ability to reduce a photo-based speed estimate to a 0.5 knot error margin when all available experts n...

Hi Jose: I think this is typical about how pointless dissagreements occur. Essentially, Bill is correct in most of the things he is saying according to much of the literature I have to hand. But we are miscommunicating on certain issues, and I cannot fully understand the points Bill is trying to mak...

... seem to be dismissing the influence of yaw while at the same time recognizing that it is one of the most fundamental variables involved in external ballistics calculations. Moreover, on occasion you make claims, as in the feasibility of inducing yaw in large projectiles (whatever defines large),...

As you will note, one has to calculate yaw before measuring drag -- at least as this method applies.

George

I take it that you are no big fan of experiments wherein small caliber projectiles are used to model effects. As you know, this technique has been in vogue for many decades, and most scientists in ballistics research are keen fans of the notion. I do note that your view on yaw effects, especially as...

... inherent yaw of a projectile is a considerable factor is determining its drag -- as is indicated in the material I forwarded to you -- which is for a 500-level ballistics course. Incidently, Dr. C. uses both FH and cemented armor in some of his penetration problems. I'll proceed as he indicates....

Hi Bill: I have been following this thread with some interest, and now find myself confused. If we are discussing drag here, then the windscreen is a central element. Yaw is also a huge factor here, and it must be determined before drag can be calculated. To do all this, we must consider... air dens...

I have some excellent material that is on point and even factors procession, etc., into the drag effect -- the so-called wobble factor. But I cannot do a cut-&-paste here to save my life. Jose, we need your help.

George